The invention relates to a shaping tool, a shaping apparatus and a method of forming a semi-finished product containing reinforcing fibers in a continuous process. The invention also relates to a device for the continuous production of components, in particular structural components for aircraft, made of fiber-reinforced composite materials.
In aircraft construction, attempts are being made to increasingly use, as load-bearing components, components which consist entirely or partly of fiber-reinforced composite materials, for example carbon fiber-reinforced plastics (CFP's). For example, DE 10 2007 062 111 A1 describes a cross-member structure which consists of carbon fiber-reinforced plastic and which serves to support the individual panels of an aircraft floor system for separating a passenger cabin from a cargo compartment arranged underneath the passenger cabin. It is also known, for example from DE 10 2004 001 078 A1 or CN 100418850, to provide segments of an aircraft fuselage with a skin and also reinforcing elements (for example, frames, stringers, etc.) made of fiber-reinforced composite materials.
In a method of manufacturing structural components for aircraft made of fiber-reinforced composite materials, a multilayer laminate may first of all be built up from fiber prepregs. The fiber prepregs may comprise a woven or nonwoven made of reinforcing fibers which are provided with a surface layer made of an uncured plastic material, for example an epoxy resin material. The building-up of the laminate may take place manually or in an automated manner. The fiber prepregs may then be brought into a desired shape for a surface section which forms the outer skin of an aircraft or for a reinforcing section which forms a frame or stringer. Finally, the plastic material which has been applied to the surfaces of the fibers is cured in an autoclave cycle under pressure and/or elevated temperature, so that a composite material having a matrix made of a cured plastic and reinforcing fibers embedded in the matrix is brought into being. An autoclave process is particularly well suited to the individual production of components having even a complex shape.
In contrast to this, EP 1 819 503 B1 describes a method for the continuous production of structural profiles which are suitable for use as structural components for aircraft. In this method, a multilayer fiber-plies arrangement is produced first of all. For this purpose, dry fiber plies are unwound from suitable rolls and fed to a pre-forming tool which brings the fiber plies into a desired preform under pressure. The pre-formed stack of fiber plies produced in the pre-forming tool is impregnated with a mixture of an epoxy resin and a curing agent, which mixture is brought, by supplying heat, to a partial reaction which brings about an increase in the viscosity of the resin. The resin-impregnated stack of fiber plies is then heated further in a cycle press and subjected to pressure so that the resin gels, that is to say the crosslinking of the resin proceeds until dimensional stability is achieved. Finally, the complete curing of the resin takes place in a tunnel oven.
Throughout the process, the fiber plies, the stack of fiber plies or the resin-impregnated stack of fiber plies are continuously conveyed to, and through, the individual stations of the process by means of suitable take-off devices. The cycle press is movably mounted so that it can be moved, together with the resin-impregnated stack of fiber plies to be pressed, over a specific distance. As soon as the treatment of one section of the resin-impregnated stack of fiber plies in the cycle press has been completed, the cycle press is opened and moved, counter to the direction of movement of the resin-impregnated stack of fiber plies, until it has reached a suitable position in which the cycle press can be closed again for treating another section of the resin-impregnated stack of fiber plies. The continuous method described in EP 1 819 503 B1 is suitable for manufacturing structural profiles with a constant cross-section in large numbers.